部分小麦高分子量谷蛋白亚基组成分析

利用十二烷基硫酸钠聚丙烯胺凝胶电泳（SDS－PAGE）分析了85个小麦材料的高分子量谷蛋白亚基的构成,其结果表明：（1）目前生产中应用的优质小麦品种,大部分具有1A上的优质亚基1,1B上的14＋15／17＋18或1D上的5＋10,个别品种还同时聚合有1A,1B,1D上的优质亚基;（2）在所分析的28个八倍体小偃麦中,多数材料含有1,2^*和5＋10等优质亚基;（3）在本实验室创造的材料中,来源于中间偃麦草和普通小麦杂交的后代材料中大部分具有14＋15亚基。此外,个别种质材料还含有Payne亚基命名系统中未命名的一些稀有的高分子量谷蛋白亚基。     

染色体工程法聚合小麦优质麦谷蛋白亚基研究

采用小偃6号ID单体材料作为受体,中优6号、安农91168和皖38为5 10亚基的供体进行杂交,F1代田间苗期取根尖进行细胞学检测,孕穗期镜检花粉母细胞选择单体植株,并对其套袋自交。F2代籽粒在室内进行SDS-PAGE电泳筛选14 15和5 10亚基聚合且纯合籽粒,将5 10优质亚基转入当地主要优质源之一的小偃6号,同时将其聚合效率与正常二体杂交F2籽粒分离结果相比较。分析认为单体材料在亚基聚合中,其亚基分离完全符合一对基因的独立遗传,具有较高的选育效率。     

小麦高分子量谷蛋白亚基效应的比较研究

采用SDS-PAGE方法,通过对5个亲本间杂交获得的F2群体每一单株的F3籽粒样本及其亲本进行小麦高分子量谷蛋白亚基（HMW-GS）组成分析,并对每一F2单株上F3籽粒群体的高分子量谷蛋白亚基组成与其籽粒蛋白质含量、SDS-沉降值的关系进行研究,分析比较黄淮麦区出现频率较高的7个亚基或亚基对的品质效应。结果表明：小麦高分子量谷蛋白亚基组成不同群体间籽粒的蛋白质含量和SDS-沉降值基本达到显著或极显著水平。优质亚基表现为：1、7＋8、14＋15和5＋10亚基。因此,黄淮麦区小麦育种应加强对这些优质亚基的引入和利用,特别是对14＋15和5＋10亚基的引入和利用。     

SDS-PAGE分析转基因小麦与主栽小麦杂交后代的高分子量麦谷蛋白亚基

目的:高分子量麦谷蛋白亚基(HMW-GS)1Ax1、1Dx5是对小麦面包烘烤品质有重要影响的优质亚基。将转基因小麦株系与普通小麦栽培品种常规杂交并快速筛选后代,以选育含有外源优质亚基的主栽小麦品系。方法:将分别含有1Ax1、1Dx5亚基的转基因小麦株系B102-1-2、B73-6-1与3种普通小麦主栽品种鄂恩1号、鄂麦12号、日喀则8号常规杂交,用不连续SDS-PAGE方法鉴定12组杂交组合(正反交)F1代311颗籽粒的HMW-GS。结果:不连续SDS-PAGE分析大量子代带型,能够快速鉴定筛选出具有优质亚基的株系,转基因获得的外源优质HMW-GS基因在大部分F1子代中能够共显性遗传。结论:常规杂交育种能使外源基因有效地整合进主栽小麦的基因组中,进一步分析后代遗传的稳定性和遗传规律就可以培育出优质的新品种;不连续SDS-PAGE快速筛选优质亚基的株系具有可操作性和实用性。     

硬粒小麦-节节麦人工合成种HMW-GS组成及1.5+10亚基的遗传分析

对C IMM YT的99份硬粒小麦—节节麦人工合成种(简称合成种)的HMW-G S组成分析发现,G lu-B 1和G lu-D 1位点的变异类型比普通小麦丰富,分别有9种和12种亚基类型;筛选出含有比5 10亚基更优质的1.5 10和5 12亚基的合成种分别有8份和1份;含有优质亚基1.5 10的合成种与普通小麦杂交结实正常;对2个合成种与2个普通小麦品种的8个正反交组合F1种子电泳发现,优质亚基1.5 10在F1代能正常表达,双亲所有亚基在F1代都得到表达,表现共显性遗传.本研究为优质亚基1.5 10和5 12转育到普通小麦中奠定了基础.     

杂交小麦‘西杂一号’种子纯度鉴定的研究

以杂种小麦新品种‘西杂一号’及其亲本为试验材料,利用A-PAGE和RAPD技术,对其进行了研究与分析.A-PAGE分析表明,亲本西农Fp-1和西农Mp-1有4条醇溶蛋白差异带,并在‘西杂一号’中表现出3对互补条带.从128个具有多态性随机引物中筛选出1个扩增带稳定、清晰且为双亲互补型的特征引物.并将这两种方法对‘西杂一号’种子纯度鉴定的结果与田间鉴定相比较,结果表明两种方法都可以用于杂种小麦杂交种及其亲本种子纯度的鉴定.     

青海糯性春小麦综合标记辅助育种研究

选用全糯小麦品种‘糯麦1号’与青海主要栽培品种‘阿勃’杂交,综合利用改良碘染色法、SDS-PAGE法和Waxy基因的分子标记等,对杂交后代进行了鉴定筛选。最终从F2代鉴定出了5粒全糯种子,从F3代鉴定出8株Wx-B1亚基缺失的植株。对全糯株系F3代的农艺性状进行评价,5个全糯株系的综合农艺性状都优于‘糯麦1号’,与‘阿勃’较接近。测定全糯株系和Wx-B1亚基缺失植株F4代种子的直链淀粉含量,5个全糯株系F4代种子的直链淀粉含量接近于0,8个Wx-B1亚基缺失植株F4代种子的直链淀粉含量在总体上比‘阿勃’的直链淀粉含量低。研究表明,采用综合标记辅助选择可快速而准确地获得适合在青海栽培的全糯和部分糯性小麦。     

湖北省优质杂交稻品种贮藏蛋白的比较研究

研究选取水稻品种共20个,其中包括湖北省近两年审定的优质杂交水稻品种10个(‘鄂早17’、‘鄂早18’、‘两优1193’、‘武香880’、‘岳优26’、‘宜优99’、‘协优96’、‘鄂晚12’、‘鄂中5号’、‘两优277’)以及7个普通杂交水稻(‘G98-202’、‘578’、‘两优637’、‘宜优22’、‘3685’、‘3089’、‘加育948’)和国家审定的优质水稻品种3个(‘嘉育948’、‘两优932’、‘舟903’),采用不连续的SDS-PAGE电泳分析种子贮藏蛋白,结果在谷蛋白中主要分离出57 kD的蛋白前体、37～39 kD的酸性亚基和22～23 kD的碱性亚基。同时,选取品种‘3089’、‘嘉育948’、‘537’、‘舟903’和‘两优932’,利用高效液相色谱法分析了种子贮藏蛋白中的谷蛋白亚基的含量。结果表明,水稻谷蛋白亚基含量的多少可以作为评价品种营养品质优劣的参考依据之一。     

转基因小麦外源优质亚基基因的杂交转育研究

在获得外源品质基因1Dx5和1Ax1超量表达的转基因小麦的基础上,利用小麦转基因品系‘B72-8-11b’和‘B102-1-2’为父本,主要以湖北省栽培品种‘鄂麦12’为母本,配置杂交组合。杂交后代中采用系谱选择法,结合HMW-GS鉴定,研究了转基因小麦外源品质基因在F1、F2、F3、F4代的传递,并筛选出外源1Dx5或1Ax1基因保持超表达的2个新型转基因株系;同时证明了将外源品质基因向栽培品种转育,是提高小麦优质亚基含量和提高HMW-GS总量的有效方法之一。     

抗条纹叶枯病香稻新品种的分子标记辅助选育

为解决上海主栽水稻品种普遍对条纹叶枯病缺乏抗性、大多数品种成熟期偏晚且食味品质不佳的状况,该研究以高产、广适性粳稻品种‘武运粳7号’为母本,与高抗条纹叶枯病水稻品系‘武2699’进行杂交,获得F1种子,再以早熟、香型优质品种‘太湖香粳’为父本,与(‘武运粳7号’ב武2699’)F_1进行复交,开展聚合育种;并分别利用与水稻抗条纹叶枯病基因QSTV-11b紧密连锁和香味控制基因Badh2共分离的分子标记,对分离世代进行辅助选择,筛选到含这2个基因的纯合基因型单株,结合田间抗性鉴定及香味测定,育成具有香味、高抗水稻条纹叶枯病、高产、优质等特点的早熟晚粳新品种‘沪香粳151’。     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.     

Composition and diversity of bird communities in Swedish farmland–forest mosaic landscapes

CapsuleThe amount of forest (at local and landscape scales) and occurrence of residual habitats at the local scale are shown to be the major factors influencing bird community composition in farmland–forest landscapes in central Sweden.

Aims To investigate the importance of local habitat and landscape structure for breeding birds in farmland–forest landscapes in central Sweden.

Methods Breeding birds were censused at 292 points. A detailed habitat mapping was made within 300 m of the points. Within a 300–600 m radius only two major habitats (forests and arable fields) were identified.

Results Cluster analyses of bird communities identified three site types that also differed in habitat composition: (i) partially forested sites in forested landscapes; (ii) heterogeneous sites with residual habitats in mosaic landscapes; and (iii) field-dominated farmland sites in open landscapes. A total of 19 of 25 farmland bird species (restricted to farmland or using both farmland and forest) had the highest abundance in farmland sites with mosaics of forest and farmland, while only six farmland species had the highest abundance in field-dominated sites. The bird community changed from being dominated by farmland species to being dominated by forest species (common in forest landscapes without farmland) at small proportions (10–20%) of forest at the local scale. A major difference in habitat composition between heterogeneous and field-dominated sites was the occurrence of different residual habitats (e.g. shrubby areas and seminatural grasslands). These habitats seemed to influence bird community composition more than land-use, despite covering <10% of the area. Seminatural grasslands were important for bird community composition and species-richness, but grazing seemed to be less important. Among different land-use types, cereal crops were the least preferred fields. Set-asides with tall vegetation and short rotation coppices were positively associated with species-richness of farmland birds.

Conclusion In general, the composition of the landscape was important for bird community composition, although amount and distribution of forests, occurrence of residual habitats and land-use of fields at the local scale had the strongest influence on bird community composition. The possible implications of these patterns for managing farmland–forest landscapes are discussed.     

Chemical constituents from the fruits of Rhus typhina L. and their chemotaxonomic significance

This work describes the isolation and characterization of twenty-nine compounds from the fruits of Rhus typhina L., including eleven flavonoids (1–11), eleven phenols (12–22), two pentacyclic triterpenes (23–24), two organic acids (25–26), one lumichrome (27), one courmarin (28) and one pyrimidine (29) on the basis of their spectroscopic data. Compounds apigenin (1), daidzein (4), orobol (5), 3′, 5, 5′, 7-tetrahydroxyflavanone (6), naringenin (7), butein (8), (-)-catechin (9), quercetin-3-O-α-L-(3″-O-galloyl)-rhamnoside (11), 2-hydroxybenzoic acid (13), 4-hydroxybenzaldehyde (14), vanillin (15), methyl 3,4-dihydroxybenzoate (16), 3,5-dihydroxybenzamide (18), tyrosol (19), caffeic acid (20), 3-(2,4,6-trihydroxyphenyl)-1-(4-hydroxyphenyl)-propan-1-one (21), phlorizin (22), friedelin (23), oleanolic acid (24), 4,4-dimethyl-heptanedioic acid (25), anthranilic acid (26), lumichrome (27), scoparone (28) and uracil (29) have not been recorded before in this plant. This is the first report on the occurrence of compounds 4–7, 9, 11, 13–14, 16, 18–21, 25–29 from the genus Rhus. Moreover, the chemotaxonomic significance of these isolated compounds was also summarized.